,
No Take Marine Protected Areas (nMPAs) as a fishery
management tool, a pragmatic perspectiveA Report to the FishAmerica Foundation
By Robert L. Shipp, Ph.D.
Annotated by Dr J Floor Anthoni
www.seafriends.org.nz/issues/war/shipp.htm
We have taken the liberty of mirroring Dr Shipp's
orignial article (in PDF) here in HTML.It contains the unabridged text of the original
article, emphasised text in red by us,augmented with our comments in blue.

Executive Summary

Marine Protected Areas (MPAs) are portions of the marine environment which
are protected from some or all human activity. Often these are proposed
as a safeguard against collapse of fish stocks, although there are numerous
other suggested purposes for their establishment. “No take” MPAs (hereafter
referenced as nMPAs) are those from which no harvest is allowed. Other
types include those where certain types of harvest are prohibited, which
are reserved for certain user groups, or which are protected from other
human activities such as drilling or dredging.
Establishment of nMPAs may have numerous beneficial purposes. However,
as a tool for fisheries management, where optimal and/or maximum sustainable
yield is the objective, nMPAs are generally not as effective as traditional
management measures, and are not appropriate for the vast majority of marine
species. This is because most marine species are far too mobile to remain
within an nMPA and/or are not overfished. For those few species that could
receive benefit, creation of nMPAs would have an adverse effect on optimal
management of sympatric forms.
Eight percent of US fish stocks of the Exclusive Economic Zone (EEZ)
are reported to be experiencing overfishing. The finfish stocks included
in this number are primarily pelagic or highly mobile species, movement
patterns that don’t lend themselves to benefit from nMPAs. Thus a very
small percentage, something less than 2 %, depending on mobility potentials,
is likely to benefit from creation of these no-take zones. However, many
of these species have come under management within the last decade, employing
more traditional fishery management measures, and are experiencing recovery.
MPAs (both “no take” and other types) can serve a positive function
as a management tool in protecting breeding aggregations, in helping recovery
of severely overfished and unmanaged insular fish populations with little
connectivity to adjacent stocks, and in protecting critical habitat which
can be damaged by certain fishing methods.

.
'

Introduction

Concept of MPAsIn recent years, a great deal of interest has been expressed in the
establishment of Marine Protected Areas (MPAs), marine “no take” areas,
or marine sanctuaries (e.g. National Research Council: “Marine Protected
Areas: Tools for Sustaining Ocean Ecosystems, 2001; National Resource Defense
Council: “Keeping Oceans Wild: How marine reserves protect our living seas,
2001”) This interest has been spurred by the frequent references to depleted
fish stocks, and continued decline in marine fishery resources.
Proponents of so called “no take” Marine Protected Areas (nMPAs) have
described the benefits to include potential as a fishery management tool
as well as several other related advantages, specifically, conserving biodiversity,
protecting (coastal) ecosystem integrity, preserving cultural heritage,
providing educational and recreational opportunities, and establishing
sites for scientific research (Houde et al., 2001). In addition, other
benefits suggested include enhancing ecotourism, and reducing user group
conflict (e.g. divers and harvesters).
The concept of nMPAs is initially attractive, and will no doubt elicit
a great deal of support and discussion among various groups interested
in protecting marine habitats. However, the many offered benefits described
above often overlap, and become intertwined in the discussions that ensue.
A
fishery management tool is one that sustains and/or increases through time
the yield of a fish stock, or several sympatric stocks of an ecosystem.
If nMPAs are to be considered as a management tool, then that goal or objective,
sustained and/or increased yield, needs to be clearly stated, and distinguished
from other, more theoretical goals.

Traditional Management ToolsTraditional management tools generally focus on reducing effort, enhancing
stocks from hatchery operations, and protecting critical habitat. Effort
reduction includes bag and size limits (including sometimes slot limits),
quotas, seasonal and/or areal closures, gear restrictions, and by-catch
reduction. These have been successful for more than a century in freshwater
environments. Their use in marine habitats has only become widespread in
the United States in recent decades, especially since passage of the Fishery
Conservation and Management Act in 1976. Hatchery operations and stocking
have also been primarily a freshwater endeavor, although recent efforts
to stock some marine species have been attempted and yet to be evaluated
over the long term. Protection of critical marine habitats has become an
issue of extreme concern and is the focus of current efforts on the part
of all Fishery Management Councils, as required in the most recent reauthorization
of the Sustainable Fisheries Act. Use of MPAs for this purpose is discussed
later in this paper.

Purposes of MPAsIn order for nMPAs to function as a management tool for marine fisheries,
there needs to be an examination in specific instances and with specific
stocks to determine the potential benefits. This is especially true when
stakeholders are currently so involved in management decisions that impact
their livelihood. In their work on no-take reserves (Murray et al., 1999),
the authors list guidelines for these reserves, including first:

1. Reserves should have clearly identified goals,
objectives, and expectations.

a) Clearly identify and describe the
purposes of each reserve.b) Clearly identify the species, communities,
and habitats to be protected.c) Clearly identify the projected role and contribution
of each reserve to the network.

I am in total agreement with these guidelines. For this reason, a systematic
approach, detailing the potential benefits or lack thereof of nMPAs on
managed stocks is justified, and is the intent of this paper. It is not
the intent of this paper to pass judgment on the benefits of MPAs (“no
take” or MPAs of other design) on any of the other stated objectives (e.g.
conserving biodiversity, study sites for ecosystem research, ecotourism
sites, protection of habitat from destructive fishing methods, protection
of habitats from other harmful anthropogenic activities such as drilling,
coastal development etc.). These are socioeconomic or scientific questions
that may have socioeconomic and/or scientific consequences, but are distinct
from evaluating scientifically nMPAs as a fishery management tool.

Methodology

The procedure followed here is to develop a comprehensive list of economically
(commercial and recreational) important finfish from the mid to south Atlantic,
the Gulf of Mexico, and Pacific US coasts (shellfish are excluded here
because of the radical differences in their life history, harvest methods,
etc.). For each species in the list, determine the status of the stocks
(underutilized, fully utilized, over utilized, unknown). Then review their
life histories, especially movement and/or migratory patterns, and make
a judgment as to the possible benefits that may be conferred by establishment
of an nMPA.

Determination of nMPA impactsNMPAs are predicated on two fundamental components:
keeping harvesters out and keeping the species in. The first of
these is primarily an enforcement, compliance, and education issue and
not to be discussed herein. The second is wholly a scientific issue, that
is, whether the biology of the species is such that they will remain within
an nMPA for a period of their life long enough to accrue the protection
desired.
Studies assessing the management potentials of nMPAs recognize this,
and the “keeping species in” component is critical in modeling efforts.
For example, Nowlis and Roberts (1998) state that their models “included
the key assumptions that adults did not cross reserve boundaries and that
larvae mixed thoroughly across the boundary but were retained sufficiently
to produce a stock-recruitment relationship for the management area.”

In addition, for an nMPA to be an effective management tool, the clear
implication is that management is needed. Thus, the stocks must be overfished,
or overfishing is occurring or likely to occur, and the stocks may be approaching
an overfished condition. There are formal and legal definitions for these
terms, but briefly, an “overfished stock” is one whose current biomass
is below that needed to maintain current harvest rates, and “overfishing”
refers to a rate of fishing pressure that will lead to the overfished
condition, even though current biomass of that stock is adequate to sustain
maximum sustainable yield (MSY) if properly managed.

If the stocks are healthy, and projected to remain
so, that is they are neither overfished nor is overfishing occurring, the
need for nMPAs as a management tool is nil. This is also true if
the preferred but complex ecosystem management strategy is employed, and
no species within the complex is overfished or experiencing overfishing.
In fact the literature is clear on this point, that if the stocks are healthy,
nMPAs at best are yield neutral or will reduce harvest in some ratio to
the size of the nMPAs (e.g. Polachek, 1990; DeMartini, 1993; Holland and
Brazee, 1996; Sladik and Roberts, 1997; Botsford et al., 1999; Hastings
and Botsford, 1999; R. Hilborn, U. of Wash. pers. com.).

Current status of fisheriesSo it is first important to gain some perspective on the extent of
overfishing in U.S. waters before we can assess the possible benefits of
nMPAs. In the latest Report to Congress (NMFS 2001), 905 fish stocks in
the EEZ were addressed, including both finfish and shellfish. Ninety-two
stocks (10%) were determined to be overfished; seventy-two stocks (8%)
were found to have overfishing occurring. Of these, 57 stocks (6.3%) were
found to be both overfished and are experiencing overfishing. These percentages
are somewhat misleading in that there were a large number of stocks for
which the stock status was undetermined. However most of these were economically
less important and less targeted species.

Determination of Potential BenefitsIn determining possible benefits for each species, while movement patterns
and stock condition are primary considerations, additional parameters include
any that may impact the management of the species. Examples include utility
and effectiveness of alternative management measures, presence of critical
habitat, by-catch mortality, release mortality, and recruitment (i.e. larval
dispersal) characteristics.

The species movement patterns of course relate to the proposed dimensions
of an nMPA, but in most discussions, vast area nMPAs, covering extents
within which a migratory species or all life history stages of sedentary
species would be contained, are not proposed. Exceptions exist in dire
cases, such as the major areas established off the upper western North
Atlantic shelf, where an attempt is being made to recover the depleted
ground fish stocks (NOAA, 1999). In fact, these can also be interpreted
as a proxy for effort reduction on a collapsed fishery. There have been
suggestions that certain areas which serve as major migratory pathways
or important spawning areas for pelagic species be considered as nMPAs
(e.g. NOAA, 1999).
These in fact will be discussed as critical habitat parameters, but
are not what are generally considered as an nMPA, as these may be seasonal,
or even variable in locale, depending on certain physical conditions.
The basic document employed for this list determination is the aforementioned
“Report on the Status of US Living Resources” published by the US Dept
of Commerce for the year 1999 (NOAA, 1999) and “The Report to Congress.
Status of Fisheries of the United States” (NMFS, 2001). These reports provide
species lists for each of the coasts, and their current stock status.
This is supplemented by including additional species that may fall
under individual state management, or have some economic importance external
to the parameters of the federal documents. Where these species have been
added, a brief commentary on the rationale to do so is included.

Thus the concern often expressed is for troubled species, and the purpose
of this report is to determine if those species are potential beneficiaries
of nMPAs.

Mid to south Atlantic speciesAnadromous Species(swimming up the rivers
to spawn)NOAA (1999) lists five managed anadromous species of the Atlantic Coast:
Striped bass, American shad, alewife/blueback, sturgeons, and Atlantic
salmon. All these stocks are considered overfished except striped bass.
Striped bass (Morone saxatilis) suffered severe recruitment failures
in the 1970s, but restrictive management measures implemented in the 1980s
and some good recruitment levels have restored the stocks. For the other
species, agricultural and industrial development and damming of rivers
are cited as the major impediments to rebuilding. And while improvements
of these riverine habitats may be necessary for recovery of these stocks,
none of these species can be considered as potential beneficiaries of an
nMPA.

Atlantic Highly Migratory Species.NOAA (1999) lists 10 categories of highly migratory fish stocks: yellowfin
tuna, bigeye tuna, albacore, skipjack tuna, bluefin tuna, “other” tunas,
swordfish, blue marlin, white marlin and sailfish. Of these, all are considered
over exploited, except yellowfin (fully exploited), skipjack (possibly
fully exploited) and other tunas (unknown). While there is grave concern
for the future of these severely overfished stocks, their highly migratory
nature and requirements for international quota regulations preclude them
from receiving significant benefit from an nMPA. However, identification
of critical spawning areas may justify seasonal/areal closures in the future.

Atlantic Shark Fishery.There are thirty-four species of sharks listed in the Atlantic shark
fishery by NOAA (1999), however these are grouped into only three categories:
large coastal, small coastal, and pelagic. The large coastal species as
a group are considered overfished, although lack of knowledge of the individual
species status is a concern. Small coastal sharks are thought to be fully
utilized, and their stock levels above that necessary to maintain a long-term
potential maximum yield. The exploitation status of the highly pelagic
grouping is unknown. But practically all shark species for which tagging
studies have been implemented show extensive movement patterns, and as
a result, are unlikely to benefit from nMPAs. However, recent information
on critical nursery areas for some species may warrant seasonal/areal closures
or other measures to protect critical habitat of juveniles.

Summer Flounder.Along the New England and mid Atlantic coast, summer flounder (Paralichthys
dentatus) of the mid Atlantic states is a heavily exploited species,
both commercially and recreationally. The species undergoes an offshore
spawning migration from late summer to mid-winter, and the larvae and post-larvae
drift inshore, where metamorphosis is completed, and the juveniles utilize
eelgrass beds or similar habitats. The extensive migratory patterns minimize
potential benefit to the species by nMPAs, however, consideration should
be given to protection and even expansion of the required juvenile habitat.

Other south Atlantic and Gulf of Mexico stocksAtlantic and Gulf of Mexico Migratory Pelagic Fisheries.
Because of their migratory patterns which ingress between both the
Gulf and south Atlantic, Gulf and Atlantic migratory species are included
together. The species listed include dolphinfish, king mackerel, Spanish
mackerel, cobia, and cero mackerel. To this list is added wahoo, because
both Management Councils (the South Atlantic Fishery Management Council
[SAFMC] and the Gulf of Mexico Fishery Management Council [GOMFMC]) have
recently begun an assessment and management plan for this species. Of these
seven species, only the Gulf stock king mackerel have been considered overfished,
although the most recent stock assessment has concluded that this stock
has now recovered to the fully utilized level (Dr. Will Patterson, chair
GOMFMC Coastal Migratory Stock Assessment Panel, pers. com). Dolphinfish,
cobia, cero, and wahoo fishery utilization levels are unknown. But in any
case, these species are so migratory that none could be considered to benefit
by an nMPA.

Atlantic and Gulf of Mexico Reef Fisheries.About 60 species of reef fishes are managed in the South Atlantic and
Gulf EEZ. For the vast majority of these, stock assessments have not been
performed and life history data, including movement patterns, are also
unknown. Thus any consideration of nMPA benefits for these species is pre
mature. However, in recent decades, great concern has been expressed for
several of the more valuable species, and more is known of their stocks
and life history than the lesser known forms. These will form the analytical
basis for the potential benefits of nMPAs, and for the present, can be
considered as reasonable proxies for the other less studied species.
The species included in this discussion are: jewfish (= goliath grouper),
Nassau grouper, gag grouper, red grouper, red snapper, vermilion snapper,
mutton snapper, greater amberjack, red porgy, and gray triggerfish. Each
of these is treated individually in regard to their stock status and current
trends, life history parameters, and potential benefits of nMPAs. Goliath
grouper (Epinephelus itajara) has been a species of great concern
for more than a decade. In fact, a total harvest prohibition was placed
on this species in the late 1980s. Since then, the population has experienced
significant recovery (A. E. Eklund, NMFS, pers.comm.), and has led many
commercial and recreational fishermen to express concern that its predatory
behavior may negatively impact populations of sympatric reef species, especially
spiny lobsters.

At the recent (January 2002) meeting of the Reef Fish Advisory Panel
(RFAP) of the GOMFMC, several members noted that these stocks have rebounded
so strongly and are impacting their prey species so heavily that the Panel
voted unanimously to request that the Council consider a controlled harvest
to determine the status of the stocks.

Nassau groupers (Epinephelus striatus) are found only in the
most extreme southern US, primarily the Florida Keys (Sadovy and Eklund,
1999). The status of their stocks has also been of great concern, especially
because of their well-documented spawning aggregations (Colin, 1992) that
make them vulnerable to intense harvest at that time. For this reason,
protection of these sites during spawning is certainly a positive function
of an nMPA. Whether these sites should be so designated permanently would
require additional studies to determine if habitat requirements were threatened
by harvest activities during other times. In addition, designation of areas
other than the spawning sites as nMPAs for protection of Nassau would not
be beneficial, since they would leave those areas during spawning, and
thus become vulnerable to capture (Bolden, 2000).

Gag grouper (Mycteroperca microlepis) is an extremely important
commercial and recreational species, occurring along the entire mid- Atlantic
and Gulf coasts. There has been a great deal of study on this species (see
Turner et al., 2001) because of its economic importance, fears for the
condition of the stock, the formation of spawning aggregations, its protogynous
(female
at birth) life cycle, and the possibility of a major shift in sex
ratios (fewer males, because females change to male
at a late age) due to overfishing and the extremely aggressive habits
of the males during this period (Coleman et al., 1996). Several regions
off the big bend area of Florida were proposed as nMPAs by the GOMFMC for
this species during the spawning period (late winter-early spring), but
prevented from implementation by subsequent litigation. However, the occurrence
of spawning aggregations and concern over sex ratios does argue for protection
in those areas well documented as spawning sites. Although the current
stock assessment indicates that the stocks are not overfished (GOMFMC,
Stock Assessment Panel [SAP], 2001), gag is definitely a potential candidate
for protection at aggregate spawning sites and during spawning periods.

Red grouper (Epinephelus morio) range from Massachusetts to Brazil,
and are most abundant on the west Florida and Yucatan shelves. They’re
found from coastal estuaries to the outer continental shelf (Robins et
al., 1986; Shipp, 2000) and will likely be declared overfished during the
year 2002 (Dr. Jim Cowan, chair, GOMFMC, SAP), although there continues
to be a great deal of uncertainty regarding the status of the stocks, due
in large part to historical catch by the Cuban fleet through the 1960s.
In addition, little is known about the migratory patterns of this species.
But there is no indication that they are any more sedentary than other
groupers, and the juveniles occur in nearshore waters, moving offshore
as they approach maturity. It is possible that adults form small breeding
aggregations (Coleman et al., 1996), but whether these occur in well-defined
areas is not known. If such areas are located, they could possibly be designated
as an nMPA during spawning periods.

Red snapper (Lutjanus campechanus) has doubtlessly become the
most controversial finfish species in the Gulf of Mexico, less so in the
south Atlantic. It’s high market value, favor by recreational fisherman,
and the vulnerability of juveniles to shrimp trawls, has resulted in stakeholder
conflicts on many fronts. The species was declared as severely overfished
in the late 1980s and early 1990s (Goodyear, 1995; Schirripa and Legault,
1999). This resulted in numerous harvest restrictions, including minimum
size limits, seasonal closures, trip limits for commercial fishermen, bag
limits for recreational fishermen, and mandates for by-catch reduction
devices by the shrimp fleet. Because of these factors, and the fact that
it’s a reef species thought to have relatively sedentary habits, several
recent papers on red snapper have cited the species as one that might be
benefited by nMPAs (Bohnsack, 1996; Fogarty et al. 2000, Houde, 2001).
However, on closer examination, red snapper would likely not benefit. Recent
papers describing results of tagging studies (Watterson et al., 1998; Patterson
et al. 2001) demonstrate that while strongly reef associated, red snappers
exhibit slow movement away from tagging sites under normal conditions,
and extensive movement as a result of tropical cyclones, a very frequent
occurrence throughout the entire range of the species (Figure 1). Thus,
a “permanent” red snapper stock in an nMPA would be largely relocated to
other areas with each of these events.

In addition, recent model projections of snapper recovery (Goodyear,
1995; Schirripa and Legault, 1999) cite the need for very substantial (40%-80%)
shrimp trawl by-catch reduction of age 0 and 1 juveniles. Red snapper larvae
remain in the plankton for two weeks or more. Thus any potential contribution
of larvae to the overall population from and nMPA stock would be subjected
to the same mortality over most of its range. But despite the stresses
experienced by the stock, red snapper appear to have begun to recover.
With the implementation of the traditional management measures described
above, quotas and CPUE have increased consistently during the last decade.

Vermilion snapper (Rhomboplites aurorubens) is a moderately important
reef species of the Gulf and south Atlantic. The stock assessment panels
have not been able with certainty to evaluate stock status. However, in
the Gulf, it is likely that this species may be heading toward an overfished
condition (J. Cowan, chair, GOMFMC Stock Assessment Panel, pers. comm.),
although the most recent assessment contained so many uncertainties that
the GOMFMC Reef Fish Advisory Panel in 2002 recommended “status quo” on
setting a quota until a more reliable assessment could be developed. The
species has been managed primarily by a minimum size limitation. There
is little information as to its migratory or movement patterns, so the
benefits of an nMPA for this species cannot be determined.

Mutton snapper (Lutjanus analis) is known to form distinct spawning
aggregations. One of the best known is the Riley’s hump area near the Dry
Tortugas in the Florida Keys. This area is protected during the spawning
season, and except for some occasional violations and attendant enforcement
problems, the protection will likely benefit the species.

Greater amberjack (Seriola dumerili, a kingfish),
though listed as a reef species, is better considered a coastal pelagic.
Although frequenting reef areas, this active species is very mobile, and
its movements, though not extensive long range migrations, do traverse
hundreds of kilometers on a regular basis (Ingram, et al., in press), and
thus is an unlikely candidate to benefit from any but the most expansive
nMPAs.

Figure 1. Polar diagrams of red snapper movement for (A) fish not at
liberty during Hurricanes Opal and Georges and (B) fish at liberty during
those hurricanes. Note scaler differences, in kilometers. From Patterson
et al, 2001

Red porgy (Pagrus pagrus, a snapper)
ranges on both sides of the Atlantic in temperate and tropical seas. It
favors live bottom habitats. It is a species of some concern regarding
the health of the stocks, especially in the south Atlantic US coast. Recent
increases in fishing pressure have resulted in a greatly reduced stock,
and a call for reduced fishing mortality. Earlier tagging studies did not
indicate extensive migrations. The species is currently under management
by the SAFMC, and effort restrictions have been put in place to reduce
harvest. Contingent on the results of this management and additional data
on population movements, the red porgy is a species that could possibly
benefit from an nMPA until stocks are returned to a level more manageable
by traditional fishery methods. However, the population appears to be experiencing
a substantial rebound (Dr. Robert Mahood, Exec. Dir. SAFMC, pers. com.),
and a new stock assessment will be completed in June of 2002.

Gray triggerfish (Balistes capriscus) is a temperate-tropical
species found on both sides of the Atlantic. The species has received additional
fishing pressure in recent years, probably resulting from more stringent
management regulations on co-occurring species, especially red snappers
and groupers. However, the stocks are not considered overfished, but as
a precautionary move, a 12” minimum TL size limit has been implemented
by most management agencies. Recent studies (Ingram, 2001) suggest that
gray triggerfish are more sedentary than previously thought, more so than
red snapper, but nevertheless do display some limited movement. Should
future fishing pressures indicate additional limitations on harvest, this
species might be the best candidate among the fishes discussed here to
benefit from an nMPA, especially given that recent stock assessment data
indicate that gray triggerfish may be experiencing local overfishing in
some locations in the Gulf of Mexico (J. Cowan, chair, GOMFMC Stock Assessment
Panel, pers. comm.).

Other Snapper/Grouper Species.In the south Atlantic, there are nine species of snappers and groupers
(gag grouper, red snapper, speckled hind, snowy grouper, Warsaw grouper,
golden tilefish, yellowtail snapper, red grouper, and black grouper) that
are considered overfished and overfishing is occurring. The SAFMC has initiated
rebuilding plans by imposing catch restrictions on all these species. These
plans are generally 10-15 year plans, and most are about five years away
from completion. If these traditional management measures fail, nMPAs might
be appropriate for some or all of these species. However, migratory
patterns of these forms are at present poorly understood. Therefore, establishment
of nMPAs at this time is pre mature.

There are an additional 19 snapper/grouper species in the South Atlantic,
as well as scores of sympatric (living in the same
native area)species under management
(e.g. grunts, porgies), for which the stock status is unknown.

Southeast Drum and Croaker Fisheries.Black drum, Atlantic croaker, spot, red drum, seatrouts, and kingfishes
(whitings) are included in this grouping. Atlantic croaker and red drum
are considered overfished, while the other species’ status is considered
unknown. All these species spawn in higher salinity waters or offshore,
and the young enter estuaries where they reside until reaching sexual maturity.
Of the two overfished stocks, management plans are in place for the
recovery of both. Croaker (Micropogonias undulatus) stocks suffer
greatly from by-catch discards, which include about 7.5 billion individuals
killed annually (NOAA 1999). Improvement in gear designs will likely reduce
this mortality and lead to recovery of the species. A total harvest ban
in federal waters by the South Atlantic and Gulf of Mexico Councils has
been put in place for red drum (Sciaenops ocellatus). In addition, the
states have implemented various restrictive harvest measures. The results
suggest that these conservation measures have substantially increased the
escapement of juveniles, and the offshore adult stocks are increasing.
Thus there appears no benefit of nMPAs as a management tool for the southeast
drum and croaker fisheries.

Other Gulf and south Atlantic species under some form of management
include striped mullet, tarpon, and snook. Only regional assessments exist
for these species, but none is considered overfished on a range-wide basis,
and all have moderate to long range migratory patterns, and would not benefit
from traditional nMPAs. However, the juvenile phase of tarpon may benefit
from some nursery area protection (Shipp, 1986).

Pacific Coast fisheries (excluding Alaska)Pacific Coast Pelagic Species.
There are five species included within the Pacific pelagic group (northern
anchovy, Pacific sardine, jack mackerel, chub mackerel, and Pacific herring,
NOAA, 1999). All are listed as under or fully utilized, none overfished.
Therefore, because of their healthy stock conditions and pelagic life history,
they would receive no benefits from creation of nMPAs.

Pacific Coast Groundfish Fisheries.The Pacific groundfish assemblage is a diverse group of species, principally
flatfishes and rockfishes. These are mainly long-lived, slow growing species,
subject to harvest by both commercial and recreational fishers. Included
are about 60 species of rockfishes, principally Sebastes and several
species of thornyheads (Genus Sebastolobus), several cods, the sablefish
(Anolopoma
fimbria) and the lingcod (Ophiodon elongatus). Recently, life
history data were provided to the Pacific States Marine Fisheries Commission
of the nearshore fishes of California (Cailliet, 2000). This, along with
several supplementary references, and combined with the NOAA document (1999)
and the Report to Congress NMFS 2001) provide the background for determination
of the possible impacts of nMPAs on these species.

The Pacific whiting (=Pacific hake, Merluccius productus), is
a mid to moderate depth species, with relatively extensive movement patterns.
It is considered fully but not over exploited, and with extremely variable
year class strengths. Because of these factors the species is not likely
to benefit from establishment of an nMPA.

The sablefish (Anaplopoma fimbria) is an important commercial
species, ranging from Japan and the Bering Sea to Baja. The stock status
is considered fully exploited, and stock levels are below optimum. However,
it is a deep water, often migratory species, thus not likely to benefit
from an nMPA.

The lingcod (Ophiodon elongatus) is a large member of the greenling
family, ranging from Kodiak Island to southern California, but is most
abundant in the northern part of its range. It is an extremely important
recreational and commercial species, with a high food value, although representing
only about 2 % of the Pacific Coast groundfish catch. This species is considered
to be over exploited, with stock levels well below that necessary to maintain
the long-term projected yield. The species is relatively sedentary, usually
in rocky reefs at depths of 10 to 100 m. It is a nest building species,
and the males become extremely aggressive during this time, particularly
vulnerable to attack by marine mammals. The species is also cannibalistic.
The life history and stock condition indicate that this species could benefit
by an nMPA in the more northern part of its range. However, other management
measures have been put in place, including protection of spawning and nesting
sites during spawning season, minimum size requirements to ensure at least
one spawn before subject to harvest, and restricted catch limits through
recreational bag limits and commercial quotas. Though recovery is likely
to be slow because this is a long-lived species (up to 25 years), these
measures are thought to be sufficient to effect recovery (Alaska Dept.
of Fish and Game, 1994).

Pacific cod (Gadus macrocephalus) is a wide ranging, highly migratory
species of commercial importance in the North Pacific. It is considered
underutilized, although stock status and long term potential yield are
unknown. Therefore, the species would not benefit from establishment of
an nMPA.

Pacific Flatfishes.Pacific halibut (Hippoglossus stenolepis) is a carefully managed
species, with its center of abundance in the Gulf of Alaska. Landings from
the US Pacific Coast (excluding Alaska) average about 570 metric tons,
representing a little more than 1% of the total harvest (NOAA, 1999). The
species is well managed throughout its range by traditional methods, and
recent harvest has been near record. Thus the species would not likely
benefit from establishment of an nMPA.

The status of four other US Pacific Coast flatfish species (arrowtooth
flounder [Atheresthes stomias], Dover sole [Microstomas pacificus]
, English sole [Pleuronectes vetulus] , and petrale sole [Eopsetta
jordani] ) are considered individually while the many additional flatfishes
are grouped together (NOAA, 1999). Of these four, none is listed as overfished,
and all are wide ranging with extensive offshore movement patterns. For
this reason, none would benefit from nMPAs. For the many remaining flatfish
species, their stock status is unknown.

Rockfishes.There are about 65 species of rockfishes endemic to the US Pacific
coast, most in the genus Sebastes. They live in a diversity of habitats,
from clean bays, to depths greater than 400 M. They are long-lived species,
with some living well over 50 years. Thus, annual exploitation to attain
the management goals of 35-40% spawning biomass per recruit is often as
low as about 5- 10%. In recent years, the surplus present in most of these
stocks has been fished down, resulting in reductions in recommended annual
harvest (NOAA, 1999).
In its report to Congress, NMFS (2001) lists 52 species of rockfish.
For four species (Pacific ocean perch [Sebastes alutus], bocaccio
[S. paucispinus], canary rockfish [S. pinniger], and cowcod
[S. levis], all but the latter are major stocks) the stocks are overfished
but overfishing is not presently occurring and rebuilding programs are
in place or under development. These species are all wide ranging forms
with extensive portions of their populations in very deep water. Thus for
fishery management purposes, nMPAs are likely not needed Only nMPAs of
impractical extent both longitudinally and bathymetrically would have any
impact on the stocks as a whole.

For three species (darkblotched rockfish [Sebastes crameri],
silvergrey rockfish [S. brevispinis], and yelloweye rockfish [S.
ruberrimus], all major stocks) overfishing is occurring, but for the former
species the stocks are not currently overfished, and for the latter two
stock conditions are unknown. Reduced mortality will be required, but currently,
rebuilding plans are not yet in place. These three are also very wide ranging,
from the Bering Sea to southern California, and out to depths of well more
than 500 M, thus nMPAs would be impractical as a management tool. And in
fact, due to the bathymetry of the eastern North Pacific coast, many of
the areas inhabited by rockfishes are such as to prevent extensive fishing
effort, or create a “natural refuge” (see Yolklavich et al. below).

For eight species (seven of which are major stocks) for which assessments
exist the stocks are not overfished, nor is overfishing occurring. For
the remaining species, most of which are minor stocks, their status and
rate of fishing mortality is unknown. Therefore, particular management
measures are premature.
The Pacific Fishery Management Council has implemented limits for individual
vessels, as well as other measures in an attempt to maintain a year round
harvest for most rockfish species. Life history data and stock assessments
for most species are not yet determined. Cailliat (2000) lists data on
about 30 species, and about half are known to be resident species. Of the
overfished or species experiencing overfishing, movement data are available
only for the canary rockfish which is considered transient/resident, with
tagged movements of over 259 km documented, and the yelloweye, which is
considered a resident species.

General Life History Comments Regarding Rockfish.In their study of the Soquel Submarine Canyon, off Monterey California,
(Yoklavich et al., 2000) suggested that “rock outcrops
of high relief interspersed with mud in deep water of narrow submarine
canyons are less accessible to fishing activities and thereby can provide
natural refuge for economically important fishes.” Their study was
represented by 52 fish species, of which rockfishes were represented by
a minimum of 24 species. In addition, they concluded that “There
was remarkable concordance between some of the guilds identified in Soquel
Canyon and the results of other habitat-specific assessments of fishes
along the west coast of the United States from central California to Alaska.”
Certainly this suggests that there is an inherent control of fishing effort
in these habitats and consideration of more extensive areas designated
as nMPAs is pre-mature and likely unnecessary.

Soh et al. (2001) studied the role of marine reserves on Alaskan rockfishes.
Although Alaska is beyond the scope of this report, the findings are likely
applicable. While predicting that harvest refugia (=MPA) can be used to
greatly reduce discards and serial overfishing, they state that the
effectiveness of marine refugia “in fisheries management is poorly understood
and concepts regarding their use are largely untested.”

Discussion

NMPAs may serve many purposes, as described above. But when intended to
serve as a fishery management tool, there are several situations for which
they may be extremely beneficial, and many others for which more traditional
methods are much preferred. These are reviewed briefly as follows.

Benefits of nMPAs as management toolsNMPAs can have a strong beneficial impact for fishery management during
periods of active spawning by aggregations, when species may be especially
vulnerable to harvest, and when certain components of the stock (e.g. large
male gag grouper) may be disproportionately liable to capture. This can
lead to imbalanced sex ratios that can further jeopardize a stressed stock.
The utility of these is likely to be seasonal, and normally would not require
year around catch restrictions.
In instances where a stock is severely overfished and subject to little
or no management, an nMPA can be used along with other measures to more
rapidly replenish populations. This is especially true in isolated, insular
populations (e.g. Roberts et al., 2001, for St Lucia) that are not strongly
connected to proximal populations for replenishment.

Where habitats are damaged by fishing practices, establishment of nMPAs
may help ensure habitat recovery. This is useful when these habitats, such
as submerged aquatic vegetation, reef structures or other hard bottom habitat,
are critical for vulnerable life stages. Oftentimes, however, gear restrictions
can be enacted to lessen the social impact that would result in declaration
of a total no-take zone.

NMPAs may also be beneficial where ecosystem management is employed
in fisheries (primarily of near sedentary species) where by-catch of non-targeted
species has become excessive, or conversely, where a protected species
has reached population levels which increase natural mortality rates of
targeted species, preventing a reasonable harvest (see comments on Goliath
grouper, above). An nMPA will allow some version of dynamic equilibrium
to return. When the equilibrium has been reestablished, then alternate,
more traditional management actions may be desirable to allow yield from
the system. However, ecosystem based management is still in its infancy,
and much research needs to be done before tested management principles
can be established.

Liabilities and “non benefits”of nMPAs as management toolsWhen establishment of an nMPA is intended as a near proxy for a virgin
stock, several factors need to be kept in mind. And it might be helpful,
in gaining perspective, to recall that some of these principles have been
well known for decades or longer, though sometimes forgotten. First, by
definition, a virgin stock provides no yield. Therefore a perfect
proxy would be a negative in terms of management goals to produce an MSY
or OY. However, proponents of nMPA usage for management purposes refer
to a “spillover effect” of harvestable adults to adjacent areas. The impact
of this spillover will always be less than that of
a properly managed stock, which generates the optimal yield-per-recruit,
again, by definition. These models are discussed in numerous classical
and modern texts (e.g. Rounsefell, 1975; Iverson, 1996).

The issue of spillover is addressed briefly by Houde et al. (2001).
The
authors describe the difficulty of direct confirmation of spillover effects,
and suggest models may be more useful in understanding how marine reserves
function in a regional context. But they also note that those conclusions
are limited by underlying assumptions on which the model is based. For
species withlow mobility, the spillover is minimal, yet these
sedentary species are the very ones for which an nMPA is supposedly most
effective.

Another claim is that larvae from an nMPA will be a significant addition
to the overall stocks. This may be beneficial, but only for a very seriously
depleted stock. In other cases, larval production,
always in excess of the carrying capacity of the habitat, does not normally
relate to year class strength.Rather density
dependent factors usually control ultimate recruitment to the harvestable
stock. While this principle has been the subject of scores of books
and probably thousands of publications, it was espoused nearly 150 years
ago by Darwin and restated frequently in most every fishery text (e.g.
Gulland, 1977; Rothschild 1986). And much more recently, data presented
by the GOMFMC Coastal Pelagic Stock Assessment Panel (January 2002) re-emphasizes
for very practical management purposes, such as in the case of Gulf king
mackerel, that egg production does not correlate
to an increase in stock size, the panel stating: “ recruitment
is assumed to increase to some level of spawning stock, and then to remain
at the average recruitment for higher spawning stock values (Figure
2).”

Stocks within an nMPAThere are numerous examples in the literature of stock increases within
an nMPA (e.g. Johnson et al., 1999; Roberts et al., 2001). However, one
must not forget what the point is here in regard to yield. While effective
nMPAs may support a stock with relatively greater biomass, perhaps larger
individuals, and a higher spawning potential ratio (SPR), this portion
of the stock has been removed from harvest . Therefore, the overall
yield is reduced by whatever fraction could be contributed to overall harvest
from this protected stock, and mitigated only by the possibility of spillover
or larval contribution, as discussed above.

Pragmatic perspectiveExamination of the scores of coastal species from the mid to south
Atlantic, Gulf, and US Pacific coasts reveals that very few species are
known to be both overfished and/or experiencing overfishing, and are sedentary.
Those candidates that are in both categories, and may possibly benefit
from and nMPA, are found in widely differing geographic ranges, with optimal
potential nMPA sites far apart (e.g. lingcod and surf perch in the Pacific,
red porgy in the Atlantic and gray triggerfish in the Gulf). To establish
an nMPA for the benefit of those few species would remove harvest potential
of the scores of sympatric forms, most of which are not overfished. And
while this may not reduce the overall harvest of these species, it would
definitely reduce efficiency and increase fishing effort in other, adjacent
areas.

Far better would be to impose more traditional methods to restore the
overfished stocks, as has been done for many species. This becomes more
and more successful as we adopt more precautionary harvest levels, improve
our methods of stock assessment, stock/recruit relationships, and life
history information.

Current plans or suggestions regarding closure
of large areas of the US mainland continental shelf to harvest are simply
not scientifically supportable from a fishery management perspective.
The suggestion, for example, that as much as 40 % of the Southern California
shelf should be designated an nMPA is totally without merit from a fishery
harvest perspective. Though there may be other aesthetic benefits, such
a closure would severely reduce harvest potentials, shift effort to other
areas, and likely have a substantial negative economic impact on both the
commercial and recreational fishing industries.

I am grateful to Drs. Ray Hilborn, University of Washington, and James
Cowan, Louisiana State University for their comments on this manuscript.
This research was funded in part by a grant from the FishAmerica Foundation
(www.fishamerica.org).

Robert L. Shipp, Ph.D. is chair of the Department of Marine Sciences,
University of South Alabama and Director of the Alabama Center for Estuarine
Studies. He administers more than $2,000,000 annually of marine and estuarine
research funds. He served nine years on the Gulf of Mexico Fishery Management
Council, twice as chair, and was chairman of the Council’s Essential Fish
Habitat Committee. He edited Systematic Zoology for 4 years, and was a
governor of the American Society of Ichthyologists and Herpetologists for
five years. He has published some 40 refereed papers and one book on marine
fishes, and has been asked to testify before Senate and National Research
Council Committees on fisheries and fishery management.